Unzip the file. You should see two folders and three files in that folder, one should be called "root-windows.bat".

Connect your Nexus 4 device to computer, then run `adb reboot-bootloader` in your computer's terminal. This will bring your device to the "fastboot" mode.

Make sure again that your bootloader is unlocked before proceeding (label found at bottom-left).

Open your computer's terminal to where you downloaded and unzipped the file, and run `root-windows` (Mac and Linux users use your own variant). You should see a red Android if the process is working.

Congrats! When the script is done, it will reboot your device and your Nexus 4 will be rooted!

This process will install the Root Check app so that you can verify a successful root.

More info:

I didn't have any trouble using these directions for rooting my Nexus 4, so if you have any troubles with the steps, then I'll try to help in my limited capacity.

Previously, when I was running Android 4.4 rooted, I used ES File Explorer to browse the root directories. But, it didn't work in Android 5.0, so instead I am now using the Root Browser app successfully.